title: Deconvoluting the reactivity of two intermediates formed from modified pyrimidines.
abstract: Generation of the 5-(2'-deoxyuridinyl)methyl radical (6) was reexamined. Trapping by 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl confirms that 6 is generated. However, trapping by methoxyamine reveals that the respective carbocation (10) is also produced. Examining the effects of these traps on products in DNA reveals that the carbocation and not 6 yields interstrand cross-links. Cross-link formation from the carbocation is consistent with DFT calculations that predict that addition at the N1 position of dA is essentially barrierless.
authors.affiliation: Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore Maryland 21218, USA.
authors.forename: Liwei
authors.initials: L
authors.lastname: Weng
authors.forename: Sonia M
authors.initials: SM
authors.lastname: Horvat
authors.forename: Carl H
authors.initials: CH
authors.lastname: Schiesser
authors.forename: Marc M
authors.initials: MM
authors.lastname: Greenberg
mesh_terms: D003432:Cross-Linking Reagents / Q000737:chemistry*; D003497:Cyclic N-Oxides / Q000737:chemistry*; D003857:Deoxyuridine / Q000031:analogs & derivatives* / Q000737:chemistry; D015394:Molecular Structure; D011743:Pyrimidines / Q000737:chemistry*; D013113:Spin Labels
chemical_list: C510308:5-(2'-deoxyuridinyl)methyl; D003432:Cross-Linking Reagents; D003497:Cyclic N-Oxides; D011743:Pyrimidines; D013113:Spin Labels; C001803:tempol; D003857:Deoxyuridine